1. The Field of the Invention
The invention is directed to test fixtures. More specifically, the invention is directed to test fixtures for use in testing optical components.
2. Description of the Related Art
Modern computing involves the transmission of large amounts of data on networks formed of two or more computers. As the processing power of computers has increased, there has been a need to keep pace with increased data handling capability across networks. One technology that facilitates the transmission of large amounts of data on the network is fiber-optics. Fiber-optics use light signals transmitted across glass or plastic fibers to communicate data. Fiber optic networks are able to transmit data at faster rates than conventional copper wire based networks. Additionally, fiber optic networks are less susceptible to noise and intrusion.
To transmit data on a fiber-optic network a light generating device is needed. Commonly, light generating devices include a laser diode or light emitting diode (LED). The light generating devices are often packaged in a TO can. The TO can has a lens in the top of the can for allowing light to be transmitted out of the can.
The TO can further includes an electrical interface such as pins or flexible circuit board traces accessible external to the TO can. The flexible circuit board trace may be soldered to other components in a system.
To receive the data on the fiber-optic and network, a device that converts light signals to electrical signals is needed. Commonly, a photodiode connected to a transimpedance amplifier is used to convert the optical signals to electrical signals. The photodiode and transimpedance amplifier are often, like the light generating devices, enclosed in a TO can.
As a part of the production process of fiber optic components, the fiber optic components often undergo testing. The testing may be for example, testing to determine functionality, performance, and ratings. Testing should be repeatable for components. For example, testing should allow components to exhibit the same characteristics when tested under the same conditions.
To test the fiber optic components, the fiber optic components are connected in conditions similar to what they would be installed in for a various applications. However, to prevent damage to the fiber optic components, they may be installed for testing using a test board that allows the fiber optic component to be connected without damaging connections on the fiber optic component. For example, it may not be desirable to solder the flexible circuit board traces as would be done in a final installation because repeated soldering and desoldering may be harmful to the fiber optic component.
One test board uses a plate that compresses the flexible circuit board traces against pins that make electrical contact to the traces. The plate is compressed onto the flexible circuit board by tightening fasteners, such as screws, against the plate. A fiber optic cable may be attached to the receptacle. In this way, various electrical or optical signals can be delivered to the fiber optic component for testing while resultant optical or electrical signals are measured.
One drawback of the test board described above relates to repeatability in testing. This is due to differences in the testing that may occur due to the flexible circuit board being in different positions in different tests. Additionally, the flexible circuit boards allow some freedom of movement of a TO can under test. Thus, a shift in the fiber optic cable connected to the TO can may cause a change in test measurements. Further, the test apparatus described above may be time consuming to use. To prepare each component for test may require a significant amount of time, including mounting and positioning the component for testing. There is therefore a need for test apparatus that allow for consistent test conditions while avoiding damage to the component under test. Further, a test apparatus that allows for quickly changing out devices under test would be useful.